Radiator header with floating tube sheet



July 4, 1939, F, 5 SEBLEY 2,154,628

RADATOR HADER WITH FLOATING .TUBE SHEET Filed Deo. 29, 1937 V INVENTOR F/Qj/Q" JT J/'/ey ATTORNEY.

Patented July 4, 1939 UNITED STATES PATENT OFFICE RADIATOR. HEADER WITH FLOATING TUBE SHEE 6 Claims.

My invention pertains to a radiator header with a oating tube sheet and to a method of assembling and balancing the same.

In the use of heat exchanger apparatus such as radiators, air conditioning and cooling units,

and similar apparatus, considerable maintenance trouble is caused by the ends of the heat exchanger tubes pulling loose from the headers. This is caused by the circulated air blowing more directly against some of the tubes which are thereby cooled or heated more than the other tubes thus causing unequal expansion and/or contraction of the tubes. This maintenance dif- A culty occurs irrespective of whether the headers are joined only by the heat exchanger tubes or also by rigid structural members.

It is accordingly an object of my invention to provide an improved method of balancing a radiator header comprising heat exchanger il) tubes and a ilexible tube sheet which consists in floating the atmospheric side of the tube sheet against a body of spongy material which serves as a balancing medium for supporting the tube sheet while permitting reverse movements of different portions thereof in accordance with the relative contraction or expansion of the different heat exchanger tubes.

It is also an object of my invention to provide a balanced radiator header comprising a plurality 39 of heat exchanger tubes, a flexible tube sheet for receiving an end of each tube, a header casing secured around the edges of the tube sheet for conducting fluid for the tubes, outside cover means disposed on the atmosphere side of the tube sheet for slidably supporting the tubes and also for enclosing a cavity to hold a balancing material, a port in said cover for injecting a body of spongy balancing material into said. cavity between the cover and the tube sheet to neat the latter in balanced relation.

It is a further object of my invention to provide a header having an abutment member rigidly secured in the header casing for engaging in supporting relation against the exlble tube sheet while the spongy fluid is being injected or packed into the cavity and adapted to be spaced from the tube sheet a predetermined distance after the cavity has been lled.

Further objects and advantages are Within the e scope of my invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details oi construction and to combinations of parts, elements, per se, and to economies of manufacture 55 and numerous other advantages, as will be apparent from a consideration of the specification in conjunction with the drawing disclosing a form of my invention, which may be preferred, in which:

Fig. l is a plan view of the improved radiator header partially broken away, and the internal construction being shown b-y the dotted lines; and

Fig. 2 is a side elevational View thereof partially broken away and sectioned to show the l0 internal construction and the cooperative relation of the elements therein disposed.

Referring more specifically to the figures of the drawing, my improved radiator header comprises a tube sheet l of a suitable gauge of sheet 1f) material to provide a flexible diaphragm like member. The tube sheet I may be made of any suitable sheet metal such as steel, bronze, iron or the like selected according to the pressure, temperature and chemical conditions of its ex- 20 posure, as will be understood. The tube sheet I is apertured and provided with nipples 3 for receiving one end of each of a plurality of spaced heat exchanger tubes 5. The edges of the nipples 3 are turned into the ends of the tubes 5 W and flared to secure the tubes in hermetically sealed relation in the tube sheet. This operation may be accomplished in any suitable manner, as will be understood, but I prefer to perform this operation in the manner disclosed and claimed :.10 in my copending patent application Serial No. 182,212 :tiled concurrently herewith.

The heater exchanger tubes 5, which are made of copper or any other metal having a suitable thermal conductivity, in accordance with the 35 usual practice, extend in spaced parallel relation for connection at the opposite ends with a suitable header which may be any conventional rigid construction (not shown). As one of my improved balanced headers is suiiicient to per- 40 mit relatively free expansion and contraction of the heat exchanger tubes, it is only necessary to provide my improved header at one end of a radiator to entirely eliminate the maintenance troubles usually caused by the stresses set up by i5 the unequal expansion and contraction of the heat exchanger tubes.

To provide for conducting a heat emitting or absorbing fluid to or from the heat exchanger tubes 5, a header casing l is provided which is of substantially dish shaped conformation having a flange 9 projecting laterally around its open edge for securement upon the peripheral edges of the tube sheet l. A pipe fitting ll, which opens from the closed side of the header casing, is in- Cil f joint therebetween.

ternally threaded for convenient connection with a pipe I2 supply line.

To support the flexible tube sheet I and prevent excessive inward distortion thereof, I provide an abutment member I3 which may be of any suitable conformation having spaced open portions I4 fitting around the nipples 3 and having closed portions disposed therebetween. For this purpose I preferably utilize a heavy plate which is suitably apertured to it over the nipples. The abutment plate I3 is secured, as by welding I5 around inside the open edge of the header casing 1 substantially flush with the laterally projecting flange 9.

Spaced from the outside, or the atmospheric pressure side, of the flexible tube sheet I, I provide an outside cover I6 which has suitable apertures' for passing the tubes 5 therethrough in snug sliding relation. The cover I6 has an offset flange I'I for tting on the edges of the tube sheet I for holding the cover in spaced relation from the tube sheet and defining a cavity I9 therebetween for receiving a balancing medium 20. An injection passage ZI extends through a lug 23 projecting from one end of the cover I5 for connecting from the cavity I9.

The header casing l and the outside cover IS may be cast of any suitable metal of a suitable thickness and weight according to the conditions of operation to which they will be exposed such as pressure, temperature, corrosion and the like.

'Ihe header casing 'I and the outside cover It are secured to opposite sides of the tube sheet- I by screws 24 passing through the edges of the tube sheet and the iianges 9 and Il which are thereby clamped on opposite sides thereof. A yieldable gasket 25 is disposed between the ange 9 of the radiator casing and the tube sheet I to conveniently provide a tight hermetically sealed The gasket 25 is made of any suitable material selected according to the conditions of operation to which it is to be exposed, as will be understood.

The thickness of the gasket 25 is particularly selected to space the abutment member 3 a predetermined distance from the inside surface of the tube sheet I such that the tube sheet can ilex freely under normal operating conditions, but it is prevented from collapsing inward under abnormal conditions. Such an abnormal condition might be caused for example if in a heating system the steam is shut off and a dirty or sticky air vent valve would not permit air replacing the condensing stream.

When my radiator header has been assembled, I inject a balancing medium such as graphite, into the cavity I9 to a pressure substantially equal to the operating pressure in the header casing, and the passage is then closed in any suitable manner, as by a plug, to retain the balancing nuid. The graphite is preferably introduced in its dry condition. Also for low pressure work, and various other conditions, a piece of rubber or cork may be placed in the cavity for a balancing medium.

In operation in heating or cooling systems, the pressure on the eXible, diaphragm-like, tube sheet I from the heating or cooling medium in the header casing is substantially balanced by the pressure of the spongy balancing fluid in the cavity I 9 on the outside of the tube sheet. In such systems air is blown across the heat exchanger tubes to conduct heat from or to the tubes, and this results in the tubes which are directly exposed to the air blast being cooled, or heated,

more than the less exposed tubes. This phenomenon causes unequal expansion and contraction of the tubes setting up stresses which loosen the ends of the tubes causing leaks in the headers. This detrimental effect occurs irrespective of whether the headers are connected by rigid structural members or only through the tubes.

In accordance with my invention the unequal expansion and contraction of the heat exchanger tubes 5 cannot injure the radiator because as some tubes expand they push the adjacent portion of the tube sheet I inwardly towaid the abutment member I3, while at the same time other tubes of the radiator which have contracted, pull the tube sheet outwardly toward the cover IB.

In this operation the spongy balancing material in the cavity I9 merely shifts from one part of the cavity to another thus continuously floating the tube sheet I and balancing it against thc pressure in the header casing. Hence, the ilexible tube sheet I substantially floats upon the spongy material in the cavity I9 in balanced relation. My improved balanced header can be conveniently installed on any conventional radiator.

In order to properly assemble and balance my improved radiator header, I rst secure the radiator casing 'l and the cover I5 to the opposite sides of the tube sheet I omitting the gasket. The spongy balancing material is now introduced into the cavity I9 in the cover to provide a balancing pressure substantially equal to the operating pressure that will be used in the header casing. During this operation, the abutment plate I3 is disposed directly adjacent the flexible tube sheet r I for rigidly supporting it against the pressure of the spongy balancing iiuid. The header casing l is then released and the gasket is inserted between it and the flue sheet. rI'he header casing I is then clamped rmly down upon the gasket in hermetically sealed relation and the header is prepared for balanced operation with the abutment plate I 3 properly spaced to permit free flexing of the tube sheet I.

It is apparent that within the scope of my invention, modificationsI and different arrangements may be made other than herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

l. The method of balancing a radiator header comprising heat exchanger tubes, a exlble tube sheet, a header casing, an abutment member therein, and a cavity enclosing outside cover plate apertured for sliding on said tubes which consists in; securing said header casing and said outside cover plate to opposite sides of said tube sheet with said abutment member abutting said tube sheet, forcing a balancing material into the cavity in the cover plate adjacent the outside of said tube sheet, releasing the header casing from the tube sheet, inserting a gasket between the header casing and the tube sheet, and securing the header casing on the gasket and the tube sheet with the abutment member spaced apart therefrom.

2. In combination in a balanced radiator header, a plurality of spaced heat exchanger tubes, a ilexible tube sheet for receiving an end of each tube, a header casing adjacent one side of said tube sheet and secured around the edges thereof for conducting fluid for the tubes, cover means disposed adjacent the other side of the tube sheet for enclosing a cavity, and a balancing material in said cavity to float said tube sheet in balanced relation thereon.

3. In combination in a radiator header, a plurality of spaced heat exchanger tubes, a tube sheet having tube receiving apertures for receiving an end of each tube in hermetically sealed relation, said tube sheet comprising a flexible diaphragm-like member which is freely yieldable to permit unequal contraction and expansion of said heat exchanger tubes, a header casing having a laterally projecting1 flange secured around the edges of said tube sheet for providing conductive connection through said heat exchanger tubes, a port in said header casing for transmitting iiuid therethrough, an abutment plate rigidly secured in said header casing adjacent the open edges thereof for supporting said tube sheet when it has been distorted more than a predetermined amount, and said abutment plate having apertures in alignment with and larger than the tubes connecting through said tube sheet to freely pass the ends of the tubes.

4. In combination in a balanced radiator header, a plurality of heat exchanger tubes disposed in spaced substantially parallel relation, a iiexible tube sheet having spaced tube receiving apertures for receiving an end of each of said heat exchanger tubes in hermetically sealed relation, a header casing open on one side, means for securing said header casing to said tube sheet around the peripheral edges thereof, an abutment plate secured inside of said header casing adjacent the open edges thereof for limiting the inward movement of said tube sheet, a port opening from said header casing for transmitting fluid therethrough, an outside cover having spaced apertures passing said tubes in snug sliding relation therethrough1 and having an offset peripheral ange for spacing it from the outside of said tube sheet for defining a cavity to hold balancing material adjacent thereto, and a gasket of a suitable thickness for insertion between the header casing and the tube sheet to properly space the abutment plate therefrom after said cavity has been packed with balancing material.

5. In combination in a` balanced radiator header, a plurality of heat exchanger tubes disposed in spaced substantially parallel relation, a iieXible tube sheet having spaced tube receiving apertures for receiving an end of each of said heat exchanger tubes in hermetically sealed relation, a header casing open on one side, means for securing said header casing to said tube sheet around the peripheral edges thereof, an abutment member secured inside of said header casing for limiting the inward movement of said tube sheet, a port opening from said header casing for transmitting fluid therethrough, an outside cover spaced from the outside of said tube sheet and secured rmly to and around the edges thereof, said outside cover having spaced apertures passing said tubes in snug sliding relation therethrough, a port opening through said outside cover into the space adjacent said tube sheet, and a balancing material packed into said space for supporting the flexible tube sheet in floating relation while permitting the reverse distortions thereof.

6. In combination in a radiator balanced header, a plurality of heat exchanger tubes disposed in spaced substantially parallel relation, a flexible tube sheet having spaced tube receiving apertures for receiving an end of each of said heat exchanger tubes in hermetically sealed relation, a header casing open on one side of substantially dish. shaped conformation with a laterally projecting fiange for securing said header casing to said tube sheet around the peripheral edges thereof, an abutment member secured inside of said header casing substantially flush with the open edges for limiting the inward movement of said tube sheet, a port opening from said header casing for transmitting fluid therethrough, an outside cover having an offset peripheral flange for spacing it from the outside of said tube sheet and fer securing it firmly around the edges thereof, said outside cover having spaced apertures passing said tubes in snug sliding relation therethrough, a port opening through said outside cover into the space adjacent said tube sheet, a balancing material packed into said space for supporting the iieXible tube sheet in floating relation while permitting the reverse distortions thereof with substantially free movement, and a gasket insertable between the header casing and the tube sheet for spacing the abutment member therefrom to support said sheet after a predetermined distortion thereof.

FLOYD J. SIBLEY.

CERTIFICATE 0E CORRECTION. Patent No'. 2,16Lh628. July l, 1959 FLOYD J.. S'IBLEY.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, second column, line l9, claim 6, for the words "radiator balanced" read balanced radiator; and that the said Letters Patent should be read with this Correction therein that the same may conform to the record ofthe case in the Patent Office.

Signed and sealed this 22nd day of' August, A. D. 1959.

Leslie Frazer (Seal) i Acting Commissioner of' Patents 

